Search Engine Algorithms

We don’t want to turn you off by getting into mathematics but it will help if you understand what an algorithm does.

Definition: An algorithm is a set of decision-making processes that are applied to a problem in order to solve that problem.

The problem the search engines have is that they must put the results for any given search into what they consider to be the order most relevant to that search. What an algorithm does in this context is to apply certain scoring factors to each web page it finds in a search and gives it a ranking “score”.

To prevent people from manipulating their results the search engines keep the details of many of these ranking factors secret. They only provide us with general guidelines on how this is done. Clearly, if anyone knew exactly how it was done they could promote their websites to the top ranking positions and make a lot of money!

Here’s a greatly simplified example of what happens within the process.

Algorithm Factors

Let’s say that a search engine algorithm judges a website page by four factors (Google probably uses more than 200). Let’s also say that these factors are:

  • Number of inbound links from other websites
  • Overall page content relevant to the search term
  • Specific search keywords found within the text on the web page
  • Title of the web page identical to or related to the search keywords.

For the purpose of this illustration, we can say that each of these factors can get a score of zero to 10. When someone enters a search engine query the algorithm looks at each of the factors in turn for each page that is found, awards an appropriate number of points and sorts the results according to the highest score. This is a very much simplified description but essentially this is what takes place when you search for information.